Electric machines have been applied as motors and generators in a wide range of industries for more than a century. A reluctance machine is an electric machine in which torque is produced by the tendency of the movable part of the machine to move into a position where the inductance of an excited winding is maximized. A switched reluctance machine is a type of a reluctance machine where the windings are energized as a function of the position of the movable part of the machine.
Conventional switched reluctance machines typically have concentrated windings around each stator pole to generate electromagnetic field. Typically, in a switched reluctance machine, depending on the number of poles in each phase, the windings around the stator poles are connected in series or parallel to create phase windings. When a phase is energized, the flux generated by the coil windings closes its path through the rotor and the closest rotor pole rotates to get in alignment with the stator pole. Due to double saliency, i.e. salient poles around both the stator and the rotor, when the rotor pole moves towards the stator pole, the airgap length, and, hence, the stored energy changes.
However, conventional switched reluctance machines often suffer from high torque ripple, low torque density, vibration and acoustic noise.